Detection of surface cracks by laser spot thermography at elevated temperature

Article type: Research Article

Authors: Qiu, Jinxing^a | Pei, Cuixiang^a; | Liu, Haochen^a | Chen, Zhenmao^a;

Affiliations: [a] Shaanxi Engineering Research Center of NDT and Structural Integrity Evaluation, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, China

Correspondence: [*] Corresponding authors: Cuixiang Pei, 28 West Xianning Road, Xian, 710049, China. Email: [email protected]. Zhenmao Chen, 28 West Xianning Road, Xian, 710049, China. E-mail: [email protected]

Abstract: The laser array spots thermography (LAST) is a new fully non-contact and non-destructive method for inspection of surface cracks. In this study, the capability of this method for inspection of surface crack in specimen at elevated temperature is investigated. The temperature distributions in a specimen at different initial temperature are calculated through simulation and measured through experiment, respectively. Both the simulation and experimental results show that the background noise in the temperature distribution will be increased when the initial temperature of the specimen is enlarged. However, with the aid of an image processing method, the surface cracks in the specimen with initial temperature from 303 K to 573 K are successfully detected by using the LAST method.

Keywords: Laser array spots thermography, surface cracks, elevated temperature, non-destructive testing

DOI: 10.3233/JAE-171195

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 4, pp. 1553-1559, 2019